• 한국건축시공학회지
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• 제20권5호
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• pp.433-440
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• 2020

콘크리트 공사에서 타설완료 후 마감작업은 표면 평활화, 수밀성 향상, 침하 및 소성수축 균열방지 등의 목적으로 반드시 실시되어야 한다. 그런데, 표면마감작업은 초결과 종결 사이의 소성상태에서 실시 되어야 하는데, 종전의 경우는 기능공의 감에 의해 결정되었다. 이에 일본의 Kato junjj는 초결의 경우 반구형 듀로미터, 종결의 경우 핀형 듀로미터로 추정하는 것을 제안한 바 있다. 그렇지만, 2개의 듀로미터를 사용함의 번잡함 및 시멘트 페이스트의 기기내부 침입으로 인한 고장의 원인이 됨에 따라 본 연구에서는 반구형 듀로미터의 침을 원주형으로 변형시킨 개량형 듀로미터로 개발하였다. 이때 개량형 듀로미터의 사용 가능성은 결합재로 플라이애시의 치환율, 골재에 Coal gasification slag의 치환율을 변화시킨 콘크리트 배합에 적용하여 사용 가능을 분석하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.6-7
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• 2018

In the previous study, durometer, namely rubber hardness tester Was used to confirm the possibility of using the setting time of concrete for determination. in this study, the possibility of using condensation time judgment condensation estimation system by comparing the measuring station setting estimation system Measuring needle of the proctor penetration resistance tester by newly making a measurement needle and refining the coagulation estimation system Want to make sure. As a result of this study, it was possible to use one condensation estimation system showing similar correlation between the two types of durometer showing high correlation with the penetration resistance value of proctor testers, It is considered to be fruitful to use the dew condensation estimation system for determining the setting time.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.37-38
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• 2022

This study is attempted to propose an appropriate number of measurements by checking and statistically analyzing the change in hardness according to the number of measurements. As a result, there was no significant difference between the 20th and 30th data, and in the 10th case, the effect on errors occurring during measurement was found to be dominant. Therefore, as the number of measurements, proposing 20 times in consideration of the convenience of use. In addition, in order to minimize the effect on the measurement error, it is proposed to remeasure the surface mane of the measurement surface and the test value in which the error occurs on the average of the test values.

• The Journal of Advanced Prosthodontics
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• 제5권3호
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• pp.270-277
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• 2013

PURPOSE. This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. MATERIALS AND METHODS. Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of $15mm{\times}10mm$ dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. RESULTS. Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. CONCLUSION. Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners.